1. Improving InSAR geodesy using Global Atmospheric Models
- Author
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Piyush Agram, Romain Jolivet, Mark Simons, Marie-Pierre Doin, Zhenghong Li, Nina Y. Lin, Gilles Peltzer, Seismological Laboratory, California Institute of Technology, California Institute of Technology (CALTECH), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Division of Geological and Planetary Sciences [Pasadena], Institut des Sciences de la Terre (ISTerre), Université Joseph Fourier - Grenoble 1 (UJF)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-PRES Université de Grenoble-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Department of Earth and Space Sciences [Los Angeles], University of California [Los Angeles] (UCLA), University of California (UC)-University of California (UC), School of Geographical and Earth Sciences, University of Glasgow, University of Glasgow, California Institute of Technology (CALTECH)-NASA, and University of California-University of California
- Subjects
010504 meteorology & atmospheric sciences ,Meteorology ,Imaging spectrometer ,[SDU.STU]Sciences of the Universe [physics]/Earth Sciences ,Deformation (meteorology) ,010502 geochemistry & geophysics ,01 natural sciences ,InSAR ,atmospheric phase screen ,Troposphere ,Geochemistry and Petrology ,Interferometric synthetic aperture radar ,Earth and Planetary Sciences (miscellaneous) ,Physics::Atmospheric and Oceanic Physics ,0105 earth and related environmental sciences ,Remote sensing ,Group delay and phase delay ,Atmospheric models ,tectonic deformations ,Geodesy ,Geophysics ,13. Climate action ,Space and Planetary Science ,Environmental science ,Global Atmospheric Models ,Satellite ,Teledetection ,Water vapor - Abstract
International audience; Spatial and temporal variations of pressure, temperature, and water vapor content in the atmosphere introduce significant confounding delays in interferometric synthetic aperture radar (InSAR) observations of ground deformation and bias estimates of regional strain rates. Producing robust estimates of tropospheric delays remains one of the key challenges in increasing the accuracy of ground deformation measurements using InSAR. Recent studies revealed the efficiency of global atmospheric reanalysis to mitigate the impact of tropospheric delays, motivating further exploration of their potential. Here we explore the effectiveness of these models in several geographic and tectonic settings on both single interferograms and time series analysis products. Both hydrostatic and wet contributions to the phase delay are important to account for. We validate these path delay corrections by comparing with estimates of vertically integrated atmospheric water vapor content derived from the passive multispectral imager Medium-Resolution Imaging Spectrometer, onboard the Envisat satellite. Generally, the performance of the prediction depends on the vigor of atmospheric turbulence. We discuss (1) how separating atmospheric and orbital contributions allows one to better measure long-wavelength deformation and (2) how atmospheric delays affect measurements of surface deformation following earthquakes, and (3) how such a method allows us to reduce biases in multiyear strain rate estimates by reducing the influence of unevenly sampled seasonal oscillations of the tropospheric delay.
- Published
- 2014
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